Dr Susan A Bartels and Dr Michael J Van Rooyen’s review published Online First in The Lancet details the devastating health effects of earthquakes and the challenges posed by these natural disasters. The authors, Dr Susan A Bartels at the Department of Emergency Medicine and Beth Israel Deaconess Medical Center Boston and Harvard Humanitarian Initiative in Boston, MA and Dr Michael J Van Rooyen, Department of Emergency Medicine, Brigham and Women’s Hospital, Boston, and Harvard Humanitarian Initiative, Boston, MA, USA state:

“Because earthquakes frequently affect populous urban areas with poor structural standards, they often result in high death rates and mass casualties with many traumatic injuries. These injuries are highly mechanical and often multisystem, requiring intensive curative medical and surgical care at a time when the local and regional medical response capacities have been at least partly disrupted. Many patients surviving blunt and penetrating trauma and crush injuries have subsequent complications that lead to additional morbidity and mortality.”

Earthquakes have caused over 780,000 deaths in the past decade alone, accounting for nearly 60% of all disaster-related mortality, and in 2004, the tsunami crisis claimed over 200,000 lives. Millions of people are exposed to earthquakes because many of the most inhabited cities in the world are built on fault lines, like Los Angeles, New York, Tokyo, Delhi and Shanghai.

Massive earthquakes have the ability to cause casualty rates that ranges from 1% to 8% amongst the endangered population, creating a large, unmet need for complex surgical and medical care as medical facilities, roads, and bridges are destroyed and medical chain supplies are interrupted. Although reports of death and injury ratios vary, many studies estimate it to be approximately1: 3, with many victims dying immediately. After the initial death toll, the second mortality peak occurs a few hours after the quake, when those with serious injuries, such as liver or spleen lacerations, pelvic fractures, and sub-dural haematomas succumb to their injuries. The third peak follows within days to weeks following a quake, as people with sepsis and multi-organ failure die of their injuries. Those suffering from chronic diseases, such as diabetes and heart conditions are also subjected to a higher death risk as crucial medicines and care is being cut off.

About 2% to 15% of the population can suffer crush injuries from heavy loads crushing their bodies. This can result in kidney problems and failure, and in severe cases even amputation. Patients, including those whose electrolyte levels appear to be normal should undergo aggressive fluid resuscitation. It is important that these fluids do not contain potassium or calcium, as crush victims already have high levels of these minerals and administering more will raise the risk of death. About half of the crush victims will develop kidney failure and half of these will need dialysis. The death toll for people with kidney failure in earthquake setting ranges from 14% to 18%.

Whilst the most common overall earthquake-related musculoskeletal injuries consist of 65% lacerations, 22% fractures and 6% soft-tissue contusions or sprains, 3 to 20% of people suffer crush injuries with 74% of these affecting people’s lower limbs. Crush victims also have a high incidence of disseminated intravascular coagulation, sepsis, adult respiratory distress syndrome, and death. Although both, amputations and fasciotomy, in which fibrous connective tissue is cut to relieve internal pressure, are controversial due to the risk of sepsis, some doctors believe it is better to amputate as soon as possible. They argue that due to electrolyte and other imbalances caused by the crushing it is better to save the patient whilst others believe that even severely crushed limbs can recover to full function.

After the earthquake in Northridge, California, heart attacks rose by 35% in the week following the disaster, with increases also being reported in other areas, including Taiwan. However, in another earthquake, in Loma Pietra, California in 1989 no increases were reported.

Compared with two previous control periods, the rates of arrhythmias after the Chinese earthquake in 2008 increased sharply by 6 and 9 times, whilst researchers noted, that after the Japanese earthquake in 1995, systolic and diastolic blood pressure increased by 15-16 mm Hg and 6-10 mm Hg respectively for 2 weeks in elderly patients who were wearing ambulatory blood pressure monitoring devices.

Other health emergencies, such as overcrowding in makeshift shelters can lead to epidemic outbreaks of infectious diseases as people are being displaced from their homes after the initial earthquake response has subsided. The impact of dead bodies during such epidemics is often dramatically overestimated by the media. The only incidence documented of corpses spreading infections to the general population is during cholera outbreaks. Sepsis is a common risk in earthquake disasters; with those affected being two-and-a-half times more likely to die compared with those without.

Other common health issues following an earthquake are post-traumatic stress and mental health problems, with reports stating that 6% to 72% of survivors suffer from depression. 17% of earthquake survivors reported to have had suicidal thoughts following the Turkey earthquake of 1999.

The numbers of fractures (36%) and fracture-dislocations (33%) are very similar. In terms of spinal fractures, burst fractures are reported to be the most common, with frequencies from 49% to 55%.

In the 1999 Taiwan earthquake 30% of people reportedly died from head injuries. After lower-limb injuries, head injuries were the second most frequent type of trauma in China in 2008.

In comparison to adults, children often have a higher risk of injury and death during earthquakes. After major earthquakes pediatric patients might be predominant, for example in Haiti, 53% of patients were below the age of 20 years and 25% were younger than 5 years. Another high-risk group compared with the general population is elderly people. According to most studies, the elderly have a higher rate of mortality compared with younger individuals and are at risk of social isolation following natural disasters, as their reactions are slower and because they might be unable or unwilling to evacuate their homes.

Written by Petra Rattue